The invention relates to a method for determining a position with the aid of radio navigation. At least one radio signal having a rotating transmission characteristic is used for this purpose. This method can be used for determining the position of a mobile object relative to at least one other mobile or stationary object, i.e. relative to at least one reference station.
A method of this kind is disclosed in principle in U.S. Pat. No. 5,157,408. This describes a determination of the relative distance and relative position of a mobile object with respect to a reference station, which features a rotating antenna for radiating a rotating radio signal. In this case, a pseudo noise coded, i.e. PN spread-spectrum signal, transmitted as the radio signal, is modulated with information on the direction of radiation of the rotating radio signal, from which the mobile object can determine its position relative to the reference station. As an alternative to this, a mobile object that can determine its position from the time difference between the time point of the receipt of the rotating radio signal with the maximum reception field strength and the transmission of a North reference signal for the North orientation of the rotating radio signal is described. The mobile object determines the relative distance by transmitting a request signal to the reference station that answers with a corresponding response signal. The mobile object can determine the relative distance to the reference station from the signal transit time or the phase shift between the request signal and response signal.
A disadvantage according to related art is that, to continuously determine the position, useful data from which the mobile object determines the orientation of the radio signal, must be transmitted to the mobile object just to determine the position and also an additional signaling is again necessary between the mobile object and reference station to determine the distance. The method according to related art continuously takes up a certain part of the transmission capacity and is therefore particularly disadvantageous for radio systems in which further data has to be transmitted by radio, such as, for example, in known radio communication systems.